7-Month Rental Bypass Proves Effective During Expansion

When the West Side sewage pump station in Onondaga County, New York, prepared to undergo its first major upgrade in more than 30 years, the project required a bypass system to move a peak flow of 30 million gallons per day (mgd). The West Side pump station is the second largest pump station in Onondaga County, taking in about 8 mgd of sewage from communities in the western suburbs and then pumping it to a nearby wastewater treatment plant. The expansion and upgrades would add more sewer capacity to reduce sewage overflows into Lake Onondaga during heavy rains, and expand its capacity and increase efficiency. The county’s Water Environment Protection Department hired local contractor C.O. Falter Construction to oversee the bypass project. The initial design called for using the station’s existing pumps during the expansion and upgrades. But it was later determined that the pump station’s existing pumps would only bear 19 mgd of water, missing the target by 25 percent. It became apparent the job would require a temporary bypass system to meet the maximum flow capacity. The contractor and pump supplier set out to design and install a temporary system to convey the full amount of flow within the same footprint as the original pumps. This helped the project avoid road closures and traffic delays. Additionally, the pump station is in a highly visible, noise-sensitive area, so loud diesel equipment was not a practical solution.

Smaller Footprint Pump Solution

To stay within the compact station area, the pump technology provider recommended using two electric submersible pumps that could plumb into the existing piping system, resulting in material cost savings. In addition to the two electric submersible pumps, the temporary bypass system at the West Side pump station also included three sound-attenuating diesel pumps, which emit only 69 decibels at 30 feet, to reduce noise pollution. One diesel pump was set up on grade away from the construction area, with the other two diesel-driven pumps serving as backups. To save energy, the team also installed a level transducer to monitor tank levels. Additionally, C.O. Falter Construction and the Water Environment Protection Department needed access to system operations when staff was not on-site. To ensure the bypass system ran smoothly during the project, a control panel with remote monitoring was installed to continuously collect data from the variable frequency drive (VFD) and transducer.

Cost Savings

The bypass system went online in March 2018 and ran through September 2018 during the expansion and upgrades. The system was set up to emulate the response and flows of the station’s permanent equipment, and remote connectivity enabled the various parties involved in the project to continually monitor the pumps from any location via a smart device. The option to rent the pumps and equipment rather than purchase them was an economic benefit for Onondaga County’s Water Environment Protection Department, providing substantial cost savings. “After learning the existing pumps couldn’t handle the project flow, it made the most sense to rent the equipment for the pump station rather than purchasing it,” the pump supplier representative said. “Renting ended up saving the customer significantly on the cost of the project.” Along with providing pumping equipment without capital expenditure, the Water Environment Protection Department had access to engineers, product experts and service technicians to ensure operations continued uninterrupted.

Remote Monitoring

The remote monitoring capability was helpful when the bypass project first began and fluctuations in the water flow varied widely due to the shifting student population at nearby Syracuse University. “Syracuse is a huge college town so there were higher flows when school was in session and then capacity dropped in the summer,” the pump supplier representative said. “That’s the beauty of remote monitoring. We can watch the equipment and do troubleshooting as needed without having to be on-site.” C.O. Falter Construction noted the ease with which anyone involved in the expansion and upgrade project could monitor the system in real-time from remote locations. “It’s pretty slick,” said Dan Falter, project manager. “If a pump goes down, we’re alerted even if we’re not on-site. The remote monitoring capability provides peace of mind, which is everything.” Along with flexibility and convenience, the remote monitoring and controls capabilities also proved more economical than the traditional manned pump watch, representing a cost savings of nearly $57,000. A successful temporary bypass setup that operated continuously for seven months provided a reliable, cost-effective, long- term solution while crews expanded and upgraded the pump station. Additionally, the solution allowed the project owner and contractor to monitor flow rates and responses in real-time from any location.